Poaceae
Arthraxon

Arthraxon prionodes (Steud.) Dandy

First published in F.W.Andrews, Fl. Pl. Sudan 3: 399 (1956)
This species is accepted
The native range of this species is NE. & E. Tropical Africa, Arabian Peninsula, Afghanistan to China and Peninsula Malaysia. It is a perennial and grows primarily in the seasonally dry tropical biome.

Descriptions

M. Thulin et al. Flora of Somalia Vol. 1-4 [updated 2008] https://plants.jstor.org/collection/FLOS

Morphology General Habit
Loosely tufted wiry perennial arising from a knotty base with silky-villous scales; stems straggling, up to 60 cm long
Morphology Reproductive morphology Inflorescences
Racemes 2–8, each 4–8 cm long; internodes ciliate to pilose, the hairs increasing in length upwards to 2–3 mm
Morphology Reproductive morphology Inflorescences Spikelets
Pedicelled spikelet narrowly lanceolate, 4–5.5 mm long, on a pedicel half as long as the internode. Sessile spikelet linear to narrowly lanceolate, 5–7 mm long; lower glume chartaceous, strongly convex, pectinate-spinose on the keels and often muricate on the back along the indistinct nerves; anthers 3, 2.5–3.5 mm long; awn of upper lemma 8–15 mm long
Distribution
N1, 2 tropical East Africa eastwards through Arabia to India, China and Thailand.
Ecology
Altitude range 1300–1700 m.
Note
A recent revision of the genus by Welzen, in Blumea 27: 255–300 (1981), places this species in A. lanceolatus. Although the two species are rather similar, the latter, which is confined to southern India, has the lower glume of the sessile spikelet more or less flat on the back and strongly nerved.
[FSOM]

Gramineae, W. D. Clayton, S. M. Phillips & S. A. Renvoize. Flora of Tropical East Africa. 1974

Morphology General Habit
Perennial, arising from a knotty base covered in silky scales.
Morphology Culms
Culms up to 60 cm. long, hard, wiry, trailing.
Morphology Leaves
Leaf-blades narrowly lanceolate to ovate, 2–7 cm. long, 4–20 mm. wide, tuberculate-ciliate on the margins, setaceously acuminate.
Morphology Reproductive morphology Inflorescences
Inflorescence of 2–8 racemes, each 4–7 cm. long; internodes pilose.
Sessile
Sessile spikelet linear to narrowly lanceolate, 5–6.5 mm. long; lower glume rounded on the back, spinously muricate on the keels and sometimes also on the indistinct dorsal nerves; awn 8–15 mm. long; 3 anthers, 2.5–3.5 mm. long.
Morphology Reproductive morphology Inflorescences Spikelets
Pedicelled spikelet narrowly lanceolate, 4–5 mm. long. Sessile spikelet linear to narrowly lanceolate, 5–6.5 mm. long; lower glume rounded on the back, spinously muricate on the keels and sometimes also on the indistinct dorsal nerves; awn 8–15 mm. long; 3 anthers, 2.5–3.5 mm. long.
Pedicelled
Pedicelled spikelet narrowly lanceolate, 4–5 mm. long.
Distribution
K1 K4 T2 U1 Sudan through Yemen and India to China and Thailand Hab. Rocky slopes1000–2000 m.
[FTEA]

Morphology General Habit
Perennial; mat forming. Rhizomes short; knotty; scaly (silky); hairy. Culms rambling; 30-60 cm long; wiry. Ligule an eciliate membrane. Leaf-blade base amplexicaul. Leaf-blades lanceolate, or ovate; 2-7 cm long; 4-20 mm wide. Leaf-blade margins tuberculate-ciliate. Leaf-blade apex attenuate.
Morphology Reproductive morphology Inflorescences
Inflorescence composed of racemes. Racemes 2-8; digitate; 4-7 cm long. Rhachis fragile at the nodes; ciliate on margins. Rhachis hairs 1-2 mm long. Rhachis internodes linear; 3-6 mm long. Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels filiform; 3-6 mm long; ciliate.
Morphology Reproductive morphology Inflorescences Spikelets
Companion sterile spikelets well-developed; lanceolate; 4-5 mm long; shorter than fertile. Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets linear to lanceolate; laterally compressed; 5-6.5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus pubescent; base truncate; attached transversely.
Sterile
Companion sterile spikelets well-developed; lanceolate; 4-5 mm long; shorter than fertile.
Fertile
Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets linear to lanceolate; laterally compressed; 5-6.5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus pubescent; base truncate; attached transversely.
Morphology Reproductive morphology Inflorescences Bracts Glume
Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; 1 length of spikelet; chartaceous; 2-keeled. Lower glume primary vein pectinately spinose. Lower glume surface convex. Upper glume lanceolate; chartaceous; 1-keeled; keeled above. Upper glume apex acute.
Morphology Reproductive morphology Flowers Florets
Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; hyaline; 2 -veined; obtuse. Fertile lemma lanceolate; hyaline; without keel; 1 -veined. Lemma apex acute; awned; 1 -awned. Principal lemma awn dorsal; arising 0.2 way up back of lemma; geniculate; 8-15 mm long overall; with twisted column. Column of lemma awn glabrous. Palea absent or minute.
Morphology Reproductive morphology Flowers
Anthers 3; 2.5-3.5 mm long.
Distribution
Africa: northeast tropical and east tropical. Asia-temperate: western Asia, Arabia, and China. Asia-tropical: India, Indo-China, and Malesia.
Reference
Andropogoneae. FTEA.
[GB]

Extinction risk predictions for the world's flowering plants to support their conservation (2024). Bachman, S.P., Brown, M.J.M., Leão, T.C.C., Lughadha, E.N., Walker, B.E. https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.19592

Conservation
Predicted extinction risk: not threatened. Confidence: confident
[AERP]

Sources

  • Angiosperm Extinction Risk Predictions v1

    • Angiosperm Threat Predictions
    • http://creativecommons.org/licenses/by/4.0

  • Flora of Somalia

    • Flora of Somalia
    • http://creativecommons.org/licenses/by-nc-sa/3.0

  • Flora of Tropical East Africa

    • Flora of Tropical East Africa
    • http://creativecommons.org/licenses/by-nc-sa/3.0

  • GrassBase - The Online World Grass Flora

    • Clayton, W.D., Vorontsova, M.S., Harman, K.T. and Williamson, H. (2006 onwards). GrassBase - The Online World Grass Flora.
    • http://creativecommons.org/licenses/by-nc-sa/3.0

  • Herbarium Catalogue Specimens

    • 'The Herbarium Catalogue, Royal Botanic Gardens, Kew. Published on the Internet http://www.kew.org/herbcat [accessed on Day Month Year]'. Please enter the date on which you consulted the system.
    • Digital Image © Board of Trustees, RBG Kew http://creativecommons.org/licenses/by/3.0/

  • Kew Backbone Distributions

    • The International Plant Names Index and World Checklist of Vascular Plants 2024. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0

  • Kew Names and Taxonomic Backbone

    • The International Plant Names Index and World Checklist of Vascular Plants 2024. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 International Plant Names Index and World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0

  • Kew Science Photographs

    • Copyright applied to individual images